a. Background Art
In an average game of golf, as many as half of the total strokes (or sometimes more) are often executed with a putter. Over the years, various techniques for that teaching of effective putting have been developed for all classes of golfers, ranging from the beginners all the way to the touring pro. Also, various teaching aids to improve the person's putting stroke have been developed over the years. A search of the U.S. patent literature has disclosed a number of such aids, these being the following:
U.S. Pat. No. 2,869,875 (Steenson) discloses what is called a "golf practice game". This patent provides two "U" shaped wickets, which can be positioned apart from one another, and a cord or string is stretched between the two wickets at a location possibly several inches or a foot above the ground surface. This cord serves as an alignment guide for the person practicing the putt or possibly a short chip shot. This is arranged so that the device can be used both indoors or outdoors. There are pivotally mounted feet at the U shaped members, and mounted to the outer end of each foot is a fork to penetrate the ground or carpet to hold the wicket in an upright position. Also, a flag or prop 12 can be provided between the wickets, and this is used in practicing a chip shot where the ball travels in flight over the flag and then strikes the ground.
U.S. Pat. No. 4,082,287 (Berkey) shows a putting guide where there is a transparent or translucent guide member that is cantilever mounted above the ground to serve as an alignment guide.
U.S. Pat. No. 4,805,913 (Hickman) shows a putting alignment guide in the form of a rectangular piece of artificial turf that is spread over a ground surface. A putting path line 20 is formed lengthwise down the center of the putting surface toward the cup.
U.S. Pat. No. 5,209,484 (Randall) shows a frame where there is a center cord positioned between ends of the frame. This is a teaching tool to instruct the player on the mechanics of the putting stroke, and this is outlined in column 4, beginning at line 16.
U.S. Pat. No. 5,273,283 (Montgomery) show a putting device that has a pair of guide rods so that the person can align his or her golf swing.
U.S. Pat. No. 4,869,501 (Battersby) shows what is called a "golf instruction apparatus and method". In this device, cords are positioned from posts at various locations and heights. This is more for a physical reference for a full golf swing, rather than provide an alignment path for the putting stroke.
U.S. Pat. No. 5,350,177 (Furbush) shows a frame which can be adjusted to various widths. This also is more of a training device for practicing the full golf swing.